The Qinghai-Tibet Plateau prototype of the 25T bus

The 25T Qinghai-Tibet Passenger Car is a plateau railway passenger car specially designed and produced for the Qinghai-Tibet Railway operation according to the special environment and climatic conditions of the Qinghai-Tibet Plateau. It is manufactured by Qingdao Sifang-Bombardier-Ball Railway Transport Equipment Co., Ltd. (BSP) ), CSR Sifang Rolling Stock Co., Ltd. and CSR Nanjing Puzhen Rolling Stock Co., Ltd. The types of Qinghai-Tibet passenger cars include hard-seat cars, hard-sleeper cars, soft-seat cars, soft-sleeper cars, dining cars, air-conditioned generator cars, official cars, etc. They are equipped with toilets, aviation airtight technology and oxygen supply devices, etc., all in dark green The body is painted with two yellow lines (but it is still different from a green car in the traditional sense). The 25T Qinghai-Tibet Bus was developed in 2001 and lasted 5 years. More than 500 technicians participated in the development, and nearly 200 component outsourcing manufacturers were involved. The overall cost is 25% to 30% higher than that of ordinary buses.

Similar to the situation of ordinary 25T buses, the 25T Qinghai-Tibet buses manufactured by two manufacturers, BSP and CSR Sifang Rolling Stock, have basically the same structure and equipment, but there are still differences in some details. For example, the air conditioner of the Qinghai-Tibet bus produced by CSR Sifang is exposed, the roof is smooth without edges, the window shape is relatively square, and the SW-220K bogie is used (except for the generator car); while the roof air conditioner of BSP products is wrapped in a fairing , not exposed, the roof has ridges, the windows are wide and flat and appear light green, and use AM96 bogies. In terms of interior design, CSR Sifang's products use white lights as the main lighting source, while BSP's Qinghai-Tibet buses use warm-toned lighting. The 25T Qinghai-Tibet buses manufactured by BSP currently only run trains between Lhasa, Tibet, Beijing, and Xining, while CSR Sifang's products are used to run between Lhasa, Shanghai, Chengdu, Chongqing, Lanzhou, and Xining.

In order to create a Tibetan-style riding environment, the interior design of the 25T Qinghai-Tibet Bus also features Tibetan cultural characteristics. In addition to patterns and ornaments with Tibetan characteristics, the five most Tibetan colors of light blue, light grey, white, saffron and saffron yellow form the main colors in the car. All information displays and signs in the carriages are in Chinese, Tibetan and English. In 2001, the State Council of the People's Republic of China officially approved the Qinghai-Tibet Railway project, and construction officially started in the same year. As the highest plateau railway with the longest mileage in the world, the special local climate environment places very stringent requirements on the Qinghai-Tibet Railway passenger cars. The Qinghai-Tibet Railway Plateau Passenger Car is a development project approved by the Ministry of Railways. The Ministry of Railways has decided to use CSR Sifang Locomotive and Rolling Stock Co., Ltd. to develop a Qinghai-Tibet Railway official diesel train in advance. It will conduct plateau tests on the train's raw materials, oxygen supply methods, anti-ultraviolet measures, etc. to accumulate experience. . In February 2003, the first plateau official EMU went online as a "mobile command vehicle" on the Qinghai-Tibet Line after undergoing a series of tests on dynamics and braking systems at the China National Railway Test Center of the Academy of Railway Sciences.

In February 2005, the Ministry of Railways of China held a public bidding for the Qinghai-Tibet Railway Passenger Car Project, and Qingdao Sifang-Bombardier-Bauer Railway Transportation Equipment Co., Ltd. (BSP) and CSR Sifang Locomotive and Rolling Stock Co., Ltd. won the bid. The development of plateau railway passenger cars was officially launched. According to the contract, the two companies need to deliver 361 plateau railway buses to the Ministry of Railways of China from December 2005 to May 2006, including 308 ordinary passenger plateau buses and 53 luxury sightseeing buses. The total contract value is US$281 million. . At the same time, the National Development and Reform Commission issued the "Notice on the Qinghai-Tibet Railway Passenger Car as a Major National Technical Equipment Research and Major Industrial Technology Development Project" stating that the Qinghai-Tibet Railway Passenger Car must rely on China's independent research and development and independent innovation.

On March 22, 2005, the Ministry of Railways of China organized a discussion on the "Plateau Adaptability Test Outline for Test Vehicles on the Qinghai-Tibet Plateau" and determined the test outline. From April 27th to 29th of the same year, the first design liaison meeting for the Qinghai-Tibet Railway Plateau Passenger Car was held in Beijing to determine the design plan for the Qinghai-Tibet Railway Passenger Car. On May 16, an expert review meeting for the bogie of the Qinghai-Tibet Railway generator car was held in Qingdao, and the feasibility of the double air spring design was determined. On May 18, CSR Sifang Co., Ltd. officially issued the Qinghai-Tibet Railway Project Implementation Plan; in the same month, two 25T test vehicles modified by CSR Sifang in accordance with plateau passenger car standards rolled off the production line. Oxygen concentrators were installed on the vehicles and the electrical system was tested. Transformation. On June 2, when Sun Yongfu, then deputy minister of the Ministry of Railways, visited Qingdao to inspect the Qinghai-Tibet Plateau test vehicle, he pointed out: "The Qinghai-Tibet passenger train must be completely designed and manufactured independently by our country. This is a major event for the revitalization of national industry." < /p>

In June 2005, the Ministry of Railways arranged a plateau adaptability test of Qinghai-Tibet Railway passenger cars, including 5 test items including air conditioning, oxygen production, noise, electrical, and braking, with the purpose of studying the plateau environment Impact on the oxygen supply system, electrical system, and air-conditioning system, verify their operational reliability, and determine the selection of main components. A scientific research team of more than 100 people and two plateau test vehicles composed of CSR Sifang Co., Ltd., BSP, the Academy of Railway Sciences, Sifang Research Institute and many manufacturers of air conditioners, oxygen generators and other important vehicle accessories went to the Qinghai-Tibet Line for testing. This test obtained a large amount of test data and performance parameters.

At the end of August 2005, the first draft of the plateau bus design was completed on the mature platform of the 25T bus.

On February 15, 2006, the first 25T Qinghai-Tibet Railway passenger car produced by BSP rolled off the production line, and the first Qinghai-Tibet Railway passenger car produced by CSR Sifang Rolling Stock also rolled off the production line in the same month. In order to ensure the high reliability of the Qinghai-Tibet Railway passenger cars operating in the plateau area, the first batch of Qinghai-Tibet Railway passenger cars from the two manufacturers conducted single-car tests, entire line tests, and trial runs on the Qinghai-Tibet line from the end of February to mid-March 2006. This period is the worst time for the weather on the Qinghai-Tibet Plateau. On June 13, 2006, all 169 plateau buses manufactured by CSR Sifang Rolling Stock were delivered for inspection and leaving the factory. In July 2006, the Chengdu Railway Bureau placed an additional order with CSR Sifang, increasing the total production of CSR Sifang's 25T Qinghai-Tibet passenger cars to 185 units.

In March 2010, in order to cooperate with the change of T164/T165 and T166/T163 trains between Shanghai and Lhasa from every other day to daily operation during the Shanghai World Expo, the Ministry of Railways issued a unified tender for a new batch of trains* **83 25T Qinghai-Tibet Railway passenger cars, including 22 hard-seat cars, 44 hard-sleeper cars, 11 soft-sleeper cars, and 6 dining cars. On April 28 of the same year, CSR Nanjing Puzhen Rolling Stock Co., Ltd. announced that it had won the bid for the production order for the Qinghai-Tibet Railway passenger car project. These buses were delivered to the Shanghai Railway Bureau in June and put into operation on July 1, 2010. The Qinghai-Tibet 25T bus adopts various new technologies to cope with the environment and climate challenges of the Qinghai-Tibet Plateau. The Ministry of Railways organized the China Academy of Railway Sciences, Sifang Rolling Stock Research Institute, bus manufacturers and other universities, research institutes and other units to conduct research on Qinghai-Tibet buses. The technical conditions and technical plans of the Qinghai-Tibet Railway were repeatedly demonstrated and the main technical plans of the Qinghai-Tibet Railway Passenger Cars were determined. Since the sections of the Qinghai-Tibet Railway with an average altitude of more than 4,000 meters account for 86% of the total length, in order to ensure the supply of oxygen in the carriages, the 25T Qinghai-Tibet Bus is equipped with an oxygen production system for the first time, using template oxygen production technology and a combination of dispersion and distributed The way. Among them, the diffuse oxygen supply is to send the oxygen-rich air with a concentration of about 40% produced by the oxygen generator into the main air duct of the air conditioner. It is mixed with the fresh air and return air in the air conditioning system and then sent into the carriages, so that the oxygen concentration in each carriage reaches 23.5% to 25%; while the oxygen concentration of distributed oxygen supply can reach 40% to 45%. Passengers can directly breathe oxygen directly through the pipeline oxygen supply port and matching nasal suction tube, ensuring the comfort of passengers on the bus. .

Due to the thin air on the plateau, the resistance value is reduced, and electrical appliances are prone to breakdown or short circuit. Therefore, the insulation requirements of the train have been increased, and the electrical wiring system has been redesigned. The insulation strength and dielectric strength have been improved in the plateau environment. More than 1.5 times, the heat dissipation capacity of heat-generating electrical appliances is required to be increased by about 30%, and simulation tests are carried out in a hypobaric oxygen chamber in advance. Due to the frequent lightning and ground rolling thunder on the Qinghai-Tibet Plateau, in order to avoid damage to the electrical system by lightning, Qinghai-Tibet buses were also equipped with a lightning protection system for the first time. Surge current absorption devices have been added to key parts such as the integrated control cabinet's DC 600V input, DC 110V input, network input, GPS and broadcast antennas, equipotential connections have been added to the vehicle end, and four sets of grounding devices have been installed on the bogie. Effectively prevents the impact of lightning strikes.

Due to the particularity of the environment along the Qinghai-Tibet Railway, trains traveling between the Tibetan Plateau and the plains actually experience two environments with greatly different conditions. Ordinary double-layer insulating glass During this process, they may deform, break, or lose their function due to changes in air pressure. The 25T Qinghai-Tibet Bus uses internal pressure automatically adjusting low-radiation insulating glass doors and windows developed by Qingdao Jinjing Co., Ltd., which not only has the performance of ordinary insulating glass, but also needs to be adapted to climate characteristics such as large air pressure changes, high radiation, and low temperature. Appropriate glass combination and air pressure adjustment device meet the special properties of anti-ultraviolet, low heat transfer and automatic adjustment of the pressure in the hollow glass cavity. The ultraviolet transmittance does not exceed 13.3%. The intensity of ultraviolet rays in the car is basically the same as that in a plain environment.

In order to improve the sealing performance of the bus, the vehicle adopts a sealed car body steel structure and a sealed bellows windshield, and for the first time uses an electronically controlled pneumatic plug door with a double-lip sealing structure to strengthen the bus. It has excellent wind and sand resistance performance and also ensures the oxygen supply effect of the bus. The shock absorber is equipped with a sand-proof rubber sleeve to prevent sand from entering the shock absorber and affecting the performance of the shock absorber. The exposed non-metallic parts of the vehicle, such as bogie air springs, bellows windshield cloth, etc., are made of highly UV-resistant materials to improve the aging resistance of the parts.

In order to protect the ecological environment of the Qinghai-Tibet Plateau, the 25T plateau bus has achieved "zero emission" for the first time, and all sewage and dirt are collected and discharged centrally. The excrement is collected centrally through a vacuum toilet collection device, and the volume can meet the requirements of continuous operation for 42 hours without discharge. The passenger car is equipped with a wastewater collection device, and the sewage tank has a capacity of 600 to 800 liters (depending on the type of carriage), which can meet the requirement of continuous operation for 18 hours without discharge. All long-distance trains on the Qinghai-Tibet Line need to carry out sewage suction and garbage recycling operations at Golmud Station. The sewage tanks, sewage tanks and garbage bins must be emptied before entering the Golmud-Lhasa section.

According to calculations, the power of a generator vehicle used in plain areas will drop by about 40% at an altitude of 5,000 meters. In order to meet the demand of 1,400 kilowatts of power supply load for the whole train in the plateau area, the 25T plateau power generation car is equipped with a high-power diesel generator set, and the power drop is controlled within 29.5% at an altitude of 5,000 meters.

At the same time, since the plateau generator car weighs 85.8 tons (the weight of the general train generator car is only more than 60 tons), it must be equipped with a specially designed SW-QD160 bogie. This kind of bogie has eight circular springs, double air springs, and uses non-wear rubber composite positioning, which can ensure that the structural speed of the bogie reaches 160 kilometers per hour when the power generation axle weighs 24 tons. In addition, in order to meet the compatibility of direct power supply to the locomotive, the 25T plateau generator locomotive adopts a DC 600V power supply method.